Low energy availability can result in impaired reproductive function for both males and females. In females, low energy availability is associated with menstrual dysfunction, including ireggualr or absent periods, as well as changes in hormones associated with the menstrual cycle. Males with low energy availability can result in reduced testosterone, as well as sperm abnormalities and erectile dysfunction. In both females and males, low energy availability can cause a reduction in sex drive.

Bone mineral density is an easily-measured marker for determining one’s bone health. Low energy availability in active individuals is associated with lower bone mineral density, increased risk of bone stress injury, and decreased bone strength. Read about bone health effects.

Low energy availability can result in impaired gastrointestinal function. Athletes with low energy availability may experience abnormal bowel movements, as well as cramping, bloating, and pain.

Low energy availability can negatively impact thyroid and metabolic function in both males and females. This can manifest as low Triiodothyronine (T3), low resting metabolic rate, reduced leptin, and/or increased cortisol.

Low energy availability can adversely affect one’s hematological function. Iron is an essential nutrient that is used in the formation of new blood cells, as well as the blood cell’s ability to carry oxygen. Low energy availability can cause low iron status, reduced ability to absorb iron, decreased hemoglobin, reduced altitude training response, and increased hepcidin concentrations.

Research has shown female athletes with low energy availability are more likely to experience urinary incontinence (urine leaking) than those with adequate energy availability.

Low energy availability can negatively affect the metabolism of glucose and lipids. Research has shown athletes with low energy availability can have reduced glucose levels, reduced insulin levels, and elevated cholesterol (total and LDL) levels.

Mental health issues can both cause and be caused by low energy availability (LEA). A diagnosed eating disorder or other medical conditions can often drive restricted energy intake, leading to the onset of REDs (7). Additionally, low energy availability has been shown to negatively impact a number of aspects of psychological well-being, including depression, eating disorders, and exercise addictions.

Low energy availability can affect aspects of neurocognitive function. This includes reduced executive function, poor cognitive flexibility, and reductions in memory, decision-making, and spatial awareness.

Low energy availability can result in sleep disturbances.

Low energy availability is associated with a range of negative impacts on the cardiovascular system. Athletes with low energy availability may have reduced blood flow, low blood pressure, and low heart rate, among other consequences.

Low energy availability can adversely affect muscles. In athletes with low energy availability, research has found reduced rates of muscle protein synthesis as well as muscle glycogen restoration.

Low energy availability (LEA) in male and female-identifying adolescents has been shown to result in stunted growth. Further, loss of menstrual function has also been implicated in disruptions in growth hormone patterns and disruptions in response to training. Read more on growth and development.

REDs has a negative impact on the immune system. Low energy availability (LEA) has been linked to greater incidences of infection and illnesses among athletes, as well as alterations in immune biomarkers.